阅读说明：本技术 一种屏蔽分压装置 (Shielding voltage divider ) 是由 龙兆芝 周峰 李文婷 殷小东 刘少波 范佳威 胡康敏 涂琛 李明 刘柯 耿志辉 于 2021-07-19 设计创作，主要内容包括：本发明公开了一种屏蔽分压装置,该装置包括阻尼电阻、高压电阻和低压电阻,其中高压电阻分为内高压电阻和外高压电阻,低压电阻也分为内低压电阻和外低压电阻,其中外高压电阻和外低压电阻串联形成了屏蔽支路,这种结构改善了测量之路的高频响应特性。另外,还在测量设备的同轴电缆上增加了第一匹配电阻和第二匹配电阻,第一匹配电阻和第二匹配电阻分别设置在同轴电缆的两端,用于减少行波在电缆内部传输的折反射引起的波形畸变。(The invention discloses a shielding voltage divider, which comprises a damping resistor, a high-voltage resistor and a low-voltage resistor, wherein the high-voltage resistor is divided into an inner high-voltage resistor and an outer high-voltage resistor, the low-voltage resistor is also divided into an inner low-voltage resistor and an outer low-voltage resistor, the outer high-voltage resistor and the outer low-voltage resistor are connected in series to form a shielding branch, and the structure improves the high-frequency response characteristic of a measured circuit. In addition, a first matching resistor and a second matching resistor are additionally arranged on a coaxial cable of the measuring equipment, and the first matching resistor and the second matching resistor are respectively arranged at two ends of the coaxial cable and used for reducing waveform distortion caused by refraction and reflection of traveling waves transmitted in the coaxial cable.)

1. A shielded voltage divider, comprising:

a damping resistor;

the high-voltage resistor is connected with the damping resistor in series and comprises an inner high-voltage resistor and an outer high-voltage resistor;

the low-voltage resistor is connected with the high-voltage resistor in series and comprises an inner low-voltage resistor and an outer low-voltage resistor;

the measuring equipment is connected with two ends of the inner low-voltage resistor in parallel;

the inner high-voltage resistor and the inner low-voltage resistor are connected in series to form a conversion branch circuit, and the outer high-voltage resistor and the outer low-voltage resistor are connected in series to form a shielding branch circuit.

2. The shielding voltage divider according to claim 1, further comprising:

an upper flange;

the outer diameter of the epoxy glass steel pipe is the same as that of the upper flange;

the lower flange has the same structure as the upper flange;

the upper flange, the lower flange and the epoxy glass steel tube form a shell of a shielding voltage divider, and the damping resistor, the high-voltage resistor and the low-voltage resistor are accommodated in the shell;

gaps are reserved among the shell, the high-voltage electric group and the low-voltage resistor, and insulating media are filled among the gaps.

3. The shielding voltage divider according to claim 1, wherein the inner high voltage resistor and the outer high voltage resistor are winding resistors, and the inner high voltage resistor and the outer high voltage resistor are wound by using the same resistance wire and have the same turn-to-turn pitch.

4. The shielded voltage divider of claim 1, wherein the ratio of said inner high voltage resistance to said inner low voltage resistance is equal to the ratio of said outer high voltage resistance to said outer low voltage resistance.

5. The shielding voltage divider according to claim 1, wherein said inner low voltage resistor and said outer low voltage resistor are formed by connecting a plurality of thick film noninductive high voltage resistors in parallel, and said inner low voltage resistor and said outer low voltage resistor are uniformly distributed on concentric circles.

6. The shielding voltage divider according to claim 1, wherein said inner low voltage resistor and said outer low voltage resistor are formed by connecting a plurality of winding resistors in parallel.

7. The apparatus of claim 1, wherein the low pressure arm housing is directly connected to the lower flange, and wherein the lower flange is grounded during testing.

8. The shielded voltage divider of claim 1, wherein said measuring device is connected in parallel to said inner low voltage resistor by a coaxial cable; and the shielding voltage division device further comprises:

one end of the first matching resistor is connected with the inner-layer low-voltage resistor in series, and the other end of the first matching resistor is connected with a core wire of the coaxial cable connecting piece; the second matching resistor is connected with the tail end of the coaxial cable in parallel;

the sum of the resistance value of the first matching resistor and the inner-layer low-voltage resistor is equal to the characteristic impedance of the radio-frequency coaxial cable; and the resistance value of the second matching resistor is equal to the wave impedance of the cable.

9. The shielding voltage divider of claim 1, further comprising:

and the equalizing ring is arranged at the top of the shielding voltage division device.

10. The shielding voltage divider according to claim 2, wherein said insulating medium is air or insulating oil.

Technical Field

The invention relates to the technical field of high voltage measurement, in particular to a shielding voltage division device.

Background

The impulse voltage measuring device is key measuring equipment for carrying out impulse voltage tolerance tests on electrical equipment, the measuring accuracy of the impulse voltage measuring device directly affects the safety and the economy of the electrical equipment, an effective method for ensuring the accuracy and the consistency of the magnitude value is magnitude traceability, and a measuring result is traced to a national standard or an international standard through an uninterrupted chain with specified uncertainty. With the continuous development of metering technology and the continuous improvement of quality management systems in recent years, and the export quantity of measuring equipment in China is increasing day by day, enterprises and research institutes pay more attention to the quantity value tracing of peak values and time parameters of impact measuring equipment, most equipment users require to calibrate the equipment regularly, and a certification/calibration certificate of a national authority is required during quality certification. Therefore, the establishment of national standard measuring devices for the impulse voltage standard in China is a problem to be solved urgently.

The impulse high-voltage divider is mainly divided into a resistance divider and a resistance-capacitance divider according to the principle, wherein the high-voltage response characteristic time of the resistance-capacitance divider is generally about hundred ns, the requirement on the high-frequency response characteristic of the divider in IEC60060.2 is not met, and the impulse high-voltage divider has an extremely low temperature coefficient and good stability, so that the resistance divider is more suitable for being used as a standard voltage dividing device. The high-voltage resistor of the resistor voltage divider is generally a winding resistor, the main influencing factor influencing the high-frequency response characteristic of the resistor voltage divider is a stray capacitance to the ground, the longer the length of the high-voltage resistor is, the larger the stray capacitance to the ground is, the larger the time constant of the voltage divider device is, and the worse the high-frequency response characteristic of the high-voltage device is. In order to reduce the length of the high-voltage resistor of the resistor divider, therefore, oil-insulated compression-type high-voltage resistors of transformers are generally used. The unit has been put forward voltage-sharing resistor divider's external electric field, voltage is higher, resistor divider's external diameter is bigger, therefore when resistor divider's rated voltage exceeded 1000kV, generally used sectional type resistor divider, its high-tension resistance runs through whole voltage divider height, the diameter is little, the restriction of voltage class is mainly for the insulation of resistance wire self, the shortcoming is high-tension resistance's height, stray capacitance to ground is big, need increase the equalizer ring at the high-tension end and carry out stray capacitance compensation to ground, but the high frequency response characteristic just can not satisfy the standard requirement.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, the shielding voltage division device provided by the invention can reduce the response time of the voltage division device, improve the stability of the scale factor and improve the high-frequency response characteristic.

The shielding voltage dividing device according to the embodiment of the first aspect of the present invention is characterized by comprising:

a damping resistor;

the high-voltage resistor is connected with the damping resistor in series and comprises an inner high-voltage resistor and an outer high-voltage resistor;

the low-voltage resistor is connected with the high-voltage resistor in series and comprises an inner low-voltage resistor and an outer low-voltage resistor;

the measuring equipment is connected with two ends of the inner low-voltage resistor in parallel;

the inner high-voltage resistor and the inner low-voltage resistor are connected in series to form a conversion branch circuit, and the outer high-voltage resistor and the outer low-voltage resistor are connected in series to form a shielding branch circuit.

The shielding voltage division device provided by the embodiment of the invention has at least the following beneficial effects: the shielding branch formed by the outer high-voltage resistor and the outer low-voltage resistor improves the stray capacitance of the equipment, and greatly reduces the response time of the voltage divider

According to some embodiments of the invention, the shielding voltage divider further comprises:

an upper flange;

the outer diameter of the epoxy glass steel pipe is the same as that of the upper flange;

the lower flange has the same structure as the upper flange;

the upper flange, the lower flange and the epoxy glass steel tube form a shell of a shielding voltage divider, and the damping resistor, the high-voltage resistor and the low-voltage resistor are accommodated in the shell;

a gap is formed inside the shell, and insulating media are filled in the gap.

According to some embodiments of the invention, the inner high voltage resistor and the outer high voltage resistor are wire-wound resistors, and the inner high voltage resistor and the outer high voltage resistor are wound by using the same resistance wire and have the same turn-to-turn pitch.

According to some embodiments of the invention, a ratio of the inner layer high voltage resistance to the inner layer low voltage resistance is equal to a ratio of the outer layer high voltage resistance to the outer layer low voltage resistance.

According to some embodiments of the invention, the inner low voltage resistor and the outer low voltage resistor are formed by connecting a plurality of thick film noninductive high voltage resistors in parallel, and the inner low voltage resistor and the outer low voltage resistor are uniformly distributed on concentric circles.

According to some embodiments of the invention, the inner low voltage resistor and the outer low voltage resistor are formed by connecting a plurality of winding resistors in parallel.

According to some embodiments of the invention, the low pressure arm housing is directly connected to the lower flange, and the lower flange is grounded during the test.

According to some embodiments of the invention, the shielding voltage dividing device further comprises:

and one end of the first matching resistor is connected with the inner-layer low-voltage resistor in series, and the other end of the first matching resistor is connected with a core wire of the coaxial cable connecting piece.

The second matching resistor is connected with the tail end of the coaxial cable in parallel;

the sum of the resistance value of the first matching resistor and the inner-layer low-voltage resistor is equal to the characteristic impedance of the radio-frequency coaxial cable; and the resistance value of the second matching resistor is equal to the wave impedance of the cable.

According to some embodiments of the invention, the shielding voltage dividing device further comprises:

and the equalizing ring is arranged at the top of the shielding voltage division device.

According to some embodiments of the invention, the insulating medium is air or insulating oil.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic circuit diagram of a shielding voltage divider according to a first embodiment of the present invention;

FIG. 2 is a schematic circuit diagram of a shielding voltage divider according to a second embodiment of the present invention'

FIG. 3 is a structural diagram of a shielding voltage divider according to a third embodiment of the present invention;

FIG. 4 is a schematic diagram of the structure of the high voltage resistor in FIG. 3;

FIG. 5 is a schematic view of the construction of the low voltage arm of FIG. 3;

the low-voltage arm comprises an inner-layer resistor 701, an outer-layer low-voltage resistor 702, a first matching resistor 600 and a lower-end metal connecting piece 503.

Damping resistor R_dInternal high voltage resistor R₁₁External high voltage resistor R₁₂Internal low voltage resistor R₂₁External low voltage resistor R₂₂The cable connector comprises a first matching resistor RM1, a second matching resistor RM2, an upper flange 100, an epoxy glass fiber reinforced plastic outer cylinder 200, a lower flange 300, an inner high-voltage resistor 401, an outer high-voltage resistor 402, an insulating inner tube 501, an insulating outer tube 502, a lower end metal connector 503, an inner ring 5031, an outer ring 5032, a first matching resistor 600, an inner low-voltage resistor 701, an outer low-voltage resistor 702, a low-voltage metal outer shell 800 and a cable connector 900

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and larger, smaller, larger, etc. are understood as excluding the number, and larger, smaller, inner, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.

The first embodiment,

Embodiments of the first aspect of the present invention provide a circuit schematic diagram of a shielded voltage divider.

Refer to fig. 1. The shielding voltage divider comprises a damping resistor R_dHigh voltage resistance, low voltage resistance and measuring equipment.

Wherein the high voltage resistor can be divided into an internal high voltage resistor R₁₁And an external high voltage resistor R₁₂(ii) a The low-voltage resistor can be divided into an inner low-voltage resistor R₂₁And outer lowVoltage resistance R₂₂. Internal high voltage resistor R₁₁And an internal low voltage resistor R₂₁Connected in series to form a switching branch circuit, an external high-voltage resistor R₁₂And an external low voltage resistor R₂₂Are connected in series to form a shielding branch. The structure of only the part of the conversion branch in the traditional equipment can greatly improve the high-frequency response characteristic of the measuring instrument by arranging the shielding branch.

The shielding branch and the conversion branch are connected in parallel to form a voltage division circuit, one side of the high-voltage resistor in the voltage division circuit is a high-voltage end, one side close to the low-voltage resistor is a low-voltage end, and the internal high-voltage resistor R₁₁And an internal low voltage resistor R₂₁The point of intermediate connection is the medium voltage end. Wherein, the low-voltage end is grounded; damping resistor R_dIs connected in series in front of the high-voltage end; the measuring device is connected to the internal low-voltage resistor R₂₁At both ends of the same. Preferably, the coaxial cable is used for wrapping the lead of the measuring equipment, and the shielding case is used for protecting the measuring equipment, so that the interference caused by the outside can be reduced, and the measuring precision is increased.

Example II,

Referring to fig. 2, according to some preferred embodiments of the present application, the shielding voltage divider described herein further includes: first matching resistor R_M1And a second matching resistor R_M2. Wherein the first matching resistor R_M1Is connected with the inner core wire of the signal output end; second matching resistor R_M2And one end of the coaxial cable is connected with the inner core wire of the coaxial cable, and the other end of the coaxial cable is connected with the reticular conducting layer of the coaxial cable.

First matching resistor R_M1The sum of the resistance value of the inner layer low-voltage resistor and the inner layer low-voltage resistor is equal to the characteristic impedance of the radio frequency coaxial cable; this structure can reduce waveform distortion caused by the refraction and reflection of traveling waves transmitted inside the coaxial cable.

Second matching resistor R_M2Is equal to the wave impedance of the cable. This configuration can further improve the matching characteristics of the shielding voltage dividing device.

Example III,

Referring to fig. 3, an embodiment of a third aspect of the present application provides a specific implementation manner of a shielding voltage divider.

The equipment comprises an upper flange 100, an epoxy glass fiber reinforced plastic outer cylinder 200, a lower flange 300, an inner high-voltage resistor 401, an outer high-voltage resistor 402, an insulating inner pipe 501, an insulating outer pipe 502, a lower end metal connecting piece 503, a first matching resistor 600, an inner low-voltage resistor 701, an outer low-voltage resistor 702, a low-voltage metal outer shell 800 and a cable connector 900.

The upper flange 100, the epoxy glass fiber reinforced plastic outer cylinder 200 and the lower flange 300 form an insulating shell of the device, and the lower flange 300 is grounded. The lower flange 300 is grounded to facilitate connection of lines, and the function of external insulation is assumed by the epoxy glass fiber reinforced plastic outer cylinder 200.

The inner high voltage resistor 401 and the outer high voltage resistor 402 are separated by an inner insulating tube 501 and an outer insulating tube 502, and the upper and lower ends are fixed by metal members, and at the same time, the metal connecting member also serves as a wire, so the metal connecting member is usually a copper connecting member.

The lower end metal connector 503 has a two-layer structure, the inner ring 5031 of the lower end metal connector 503 is electrically contacted with the inner high-voltage resistor 401, and the outer ring 5032 is electrically contacted with the outer high-voltage resistor 402. The inner low-voltage resistor 701 is connected to the inner ring 5031 of the lower end metal connector 503, and the outer low-voltage resistor 702 is connected to the outer ring 5032 of the lower end metal connector. Wherein the inner and outer races 5031, 5032 are electrically isolated from one another.

The low voltage metal housing 800 protects the inner 701 and outer 702 low voltage resistors and supports the overall structure.

One end of the first matching resistor 600 is connected to the inner ring of the lower end metal connector, and the other end is connected to the cable connector 900. The other end of the cable connector 900 is connected to the coaxial cable and the measuring device.

According to some preferred embodiments of the present application, an insulating medium is filled in a gap formed between an insulating housing and other internal structures of the device, which is formed by the upper flange 100, the epoxy glass fiber reinforced plastic outer cylinder 200 and the lower flange 300, and generally, the insulating medium is air or insulating oil, and the insulating oil can help to dissipate heat, stabilize a scale factor, and reduce the manufacturing cost and the maintenance cost of the device by using air.

Example four,

According to some preferred embodiments of the present application, the shielding voltage divider can be further improved on the basis of the third embodiment.

Fig. 4 is a schematic structural diagram of the high-voltage resistor of the shielding voltage divider described in the third embodiment.

An inner high-voltage electric group 401 formed by connecting two resistance wires in parallel is wound on the outer wall of the insulating inner tube 501; one resistance wire is wound clockwise and the other is wound counterclockwise. The winding method is called a non-inductive winding resistance method, and belongs to a common technical means in impact measurement.

An outer high-voltage resistor 402 formed by connecting two resistance wires in parallel is wound on the outer wall of the insulating outer tube 502. The winding mode of the two resistance wires is the same as that of the two resistance wires of the inner high-voltage resistor 401, and the achieved effect is also the same.

According to some preferred embodiments of the present application, the inner and outer insulating tubes 501 and 502 have double spiral grooves with left and right turns having a uniform turn-to-turn pitch, and the gamma wire is wound in the spiral grooves. The inner high-voltage resistor 401 and the outer high-voltage resistor 402 are both winding resistors, and are wound by using the same resistance wires, and the turn-to-turn distances are consistent. The structure can ensure that the point positions at the same height of the internal resistor and the external resistor are equal, thereby greatly reducing the stray capacitance to the ground of the high-voltage resistor at the inner layer and improving the high-frequency response characteristic of the voltage conversion branch circuit. And the heating of the resistance wire is half less than that of the common resistance voltage divider, so that the stability of the scale factor is improved.

According to some preferred embodiments of the present application, the proportionality ratio of the internal high voltage resistor 401 to the internal low voltage resistor 701 is equal to the proportionality ratio of the external high voltage resistor 402 to the external low voltage resistor 702. The structure can also ensure that the electric potentials on the inner layer and the outer layer of the low-voltage resistor are consistent, and the shielding effect is improved.

Fig. 5 is a schematic diagram of the structure of the low pressure arm in the shielding and voltage dividing device described in the present application. The low-voltage arm comprises an inner-layer low-voltage resistor 701, an outer-layer low-voltage resistor 702, a first matching resistor 600 and a lower-end metal connecting piece 503.

The structure of the lower end metal connecting member 503 is shown in fig. 5. The high-voltage resistor type transformer comprises an inner ring 5031 and an outer ring 5032, wherein the inner ring 5031 is electrically connected with an inner high-voltage resistor 401 (not shown in the figure), and the outer ring 5032 is electrically connected with an outer high-voltage resistor set 402 (not shown in the figure).

The inner low-voltage resistor 701 and the outer low-voltage resistor 702 are of a structure formed by connecting a plurality of thick-film non-inductive high-voltage resistors in parallel and are uniformly distributed on a concentric circle. This structure can reduce stray inductance values and reduce waveform distortion.

According to some preferred embodiments of the present application, the ratio of the inner high voltage resistance 401 to the inner low voltage resistance 701 is equal to the ratio of the outer high voltage resistance to the outer low voltage resistance.

According to some preferred embodiments of the present application, the shielding voltage divider further includes a grading ring and a damping resistor (not shown in the figure), and the damping resistor and the grading ring are disposed at the top end of the whole voltage divider, so that the stray capacitance to ground of the high voltage arm can be compensated by using the stray capacitance generated between the damping resistor and the grading ring.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.